Method of forming dielectric film and capacitor manufacturing method using the same

Abstract

In a method of manufacturing a capacitor, a lower electrode of a capacitor is formed on or above a semiconductor substrate. An ozone gas and an inert gas are simultaneously introduced for a predetermined period into a reaction chamber of an atomic layer deposition apparatus in which the semiconductor substrate is set. Then, the ozone gas is exhausted from the reaction chamber by stopping the introduction of the ozone gas and introducing only the inert gas into the reaction chamber, after the introduction. A capacitive dielectric film is formed on the lower electrode by an atomic layer deposition (ALD) method in the atom layer deposition apparatus. An upper electrode of the capacitor is formed on the capacitive dielectric film after the capacitive dielectric film is formed.

What is claimed is: 
     
       1. A method of manufacturing a capacitor, comprising:
 forming a lower electrode of a capacitor on or above a semiconductor substrate; 
 introducing an ozone gas and an inert gas simultaneously for a predetermined period into a reaction chamber of an atomic layer deposition apparatus in which said semiconductor substrate is set; 
 exhausting said ozone gas from said reaction chamber by stopping the introduction of said ozone gas and introducing only said inert gas into said reaction chamber, after said introducing said ozone gas and said inert gas: 
 forming a capacitive dielectric film on said lower electrode by an atomic layer deposition (ALD) method in said atomic layer deposition apparatus, after said exhausting said ozone gas from said reaction chamber: and 
 forming an upper electrode of said capacitor on said capacitive dielectric film after said capacitive dielectric film is formed, 
 wherein said introducing the ozone gas and inert gas simultaneously is performed after said forming the lower electrode and prior to said forming the capacitive dielectric film on the lower electrode. 
 
     
     
       2. The method according to  claim 1 , wherein said exhausting said ozone gas from said reaction chamber comprises:
 stopping the introduction of said ozone gas and said inert gas; 
 exhausting said reaction chamber to a lower pressure vacuum state after said stopping; and 
 introducing only said inert gas into said reaction chamber, after said exhausting said reaction chamber to a vacuum state. 
 
     
     
       3. The method according to  claim 2 , wherein said exhausting the ozone gas from the reaction chamber comprises:
 repeating said exhausting said reaction chamber to a vacuum state and said introducing only said inert gas into said reaction chamber. 
 
     
     
       4. The method according to  claim 1 , wherein said predetermined period comprises a period in a range from 1 second to 120 seconds. 
     
     
       5. The method according to  claim 1 , wherein said predetermined period comprises a period in a range from 40 seconds to 120 seconds. 
     
     
       6. The method according to  claim 1 , wherein a process temperature in each of said introducing the ozone gas and the inert gas simultaneously and said exhausting the ozone gas from the reaction chamber, is substantially same as a process temperature in said forming the capacitive dielectric film on the lower electrode. 
     
     
       7. The method according to  claim 1 , further comprising:
 forming an oxidization preventing film on said lower electrode after said forming a lower electrode of a capacitor and before said introducing the ozone gas and the inert gas simultaneously for a predetermined period into the reaction chamber. 
 
     
     
       8. The method according to  claim 1 , wherein said forming the capacitive dielectric film comprises:
 introducing a material gas which contains a material of a capacitive insulating film into said reaction chamber; 
 introducing the inert gas in said reaction chamber to purge said material gas; and 
 introducing an oxidation gas necessary for oxidation reaction into said reaction chamber, and 
 wherein said inert gas used to purge said material gas is the same as the inert gas simultaneously introduced with the ozone gas and the inert gas introduced into said reaction chamber alter exhausting and prior to forming the capacitive dielectric film on said lower electrode. 
 
     
     
       9. The method according to  claim 8 , wherein said oxidation gas used in said introducing said oxidation gas necessary for oxidation reaction into said reaction chamber comprises an ozone gas. 
     
     
       10. The method according to  claim 8 , wherein said capacitive dielectric film comprises at least one of an amorphous aluminum oxide film, an amorphous hafnium oxide film and an amorphous zirconium oxide film. 
     
     
       11. A method of forming a dielectric film, comprising:
 setting a semiconductor substrate on which a lower layer structure has been formed, in a reaction chamber of an atomic layer deposition apparatus; 
 introducing an ozone gas and an inert gas simultaneously into said reaction chamber for a predetermined period; 
 exhausting said ozone gas from said reaction chamber by stopping the introduction of said ozone gas and introducing only said inert gas into said reaction chamber; and 
 forming a dielectric film on said lower layer structure by an atomic layer deposition (ALD) method in said atomic layer deposition apparatus. 
 
     
     
       12. A method of manufacturing a semiconductor device, comprising:
 forming a dielectric film over a semiconductor substrate by use of an atomic layer deposition method, wherein the atomic layer deposition method comprises:
 supplying a metal source gas to the semiconductor substrate; 
 supplying an oxygen source gas to the semiconductor substrate in place of the metal source gas; and 
 repeating said supplying a metal source gas and said supplying an oxygen source gas at least one time to thereby form the dielectric film; and 
 
 performing a preprocessing operation over the semiconductor substrate prior to forming the dielectric film by use of the atomic layer deposition method, wherein performing a preprocessing operation comprises: 
 supplying an oxygen source gas and an inert gas to the semiconductor substrate: 
 stopping supplying the oxygen source gas; and 
 exhausting the oxygen source gas. 
 
     
     
       13. The method according to  claim 12 , wherein the oxygen source gas employed in the atomic layer deposition method and the oxygen source gas employed in the preprocessing operation comprise an ozone gas. 
     
     
       14. The method according to  claim 13 , further comprising:
 after exhausting the oxygen source gas, supplying inert gas to the semiconductor substrate. 
 
     
     
       15. The method according to  claim 12 , wherein during the preprocessing operation the semiconductor substrate is heated to a temperature between 250° C. to 500° C. 
     
     
       16. The method according to  claim 14 , wherein the exhausting of the oxygen source gas and the supplying of the inert gas to the semiconductor substrate is repeated a plurality of times. 
     
     
       17. The method according to  claim 12 , further comprising placing the semiconductor substrate in a reaction chamber, a pressure inside the reaction chamber ranging from 0.133 Pa and 13.3 Pa. 
     
     
       18. The method according to  claim 12 , wherein the preprocessing operation includes applying vacuum during said exhausting the oxygen source gas. 
     
     
       19. The method according to  claim 12 , wherein the oxygen source gas is supplied to the semiconductor substrate through a delivery system, the delivery system also being utilized to supply the metal source gas.